package com.module.utils;

/**
 * @author: Mr.Zhong
 * @create: 2018-07-04 16:01
 * @description:
 **/

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.security.SecureRandom;

/**
 *  * DES加密解密
 *  *
 *  * @author z77z
 *  * @datetime 2017-3-13
 *  
 */
public class DESUtil {
    /**
     *    * DES算法密钥
     *    
     */

    private static final byte[] DES_KEY = {21, 1, -110, 82, -32, -85, -128, -65};

    /**
     *    * 数据加密，算法（DES）
     *    *
     *    * @param data
     *    *      要进行加密的数据
     *    * @return 加密后的数据
     *    
     */

    @SuppressWarnings("restriction")
    public static String encryptBasedDes(String data) {
        String encryptedData = null;
        try {
// DES算法要求有一个可信任的随机数源
            SecureRandom sr = new SecureRandom();
            DESKeySpec deskey = new DESKeySpec(DES_KEY);
// 创建一个密匙工厂，然后用它把DESKeySpec转换成一个SecretKey对象
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            SecretKey key = keyFactory.generateSecret(deskey);
// 加密对象
            Cipher cipher = Cipher.getInstance("DES");
            cipher.init(Cipher.ENCRYPT_MODE, key, sr);
// 加密，并把字节数组编码成字符串
            encryptedData = new sun.misc.BASE64Encoder().encode(cipher.doFinal(data.getBytes()));
        } catch (Exception e) {
// log.error("加密错误，错误信息：", e);
            throw new RuntimeException("加密错误，错误信息：", e);
        }
        return encryptedData;
    }

    /**
     *    * 数据解密，算法（DES）
     *    *
     *    * @param cryptData
     *    *      加密数据
     *    * @return 解密后的数据
     *    
     */

    @SuppressWarnings("restriction")
    public static String decryptBasedDes(String cryptData) {
        String decryptedData = null;
        try {
// DES算法要求有一个可信任的随机数源
            SecureRandom sr = new SecureRandom();
            DESKeySpec deskey = new DESKeySpec(DES_KEY);
// 创建一个密匙工厂，然后用它把DESKeySpec转换成一个SecretKey对象
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            SecretKey key = keyFactory.generateSecret(deskey);
// 解密对象
            Cipher cipher = Cipher.getInstance("DES");
            cipher.init(Cipher.DECRYPT_MODE, key, sr);
// 把字符串解码为字节数组，并解密
            decryptedData = new String(cipher.doFinal(new sun.misc.BASE64Decoder().decodeBuffer(cryptData)));
        } catch (Exception e) {
// log.error("解密错误，错误信息：", e);
            throw new RuntimeException("解密错误，错误信息：", e);
        }
        return decryptedData;
    }


    public static void main(String[] args) {
        String str = "123456";
// DES数据加密
        String s1 = encryptBasedDes(str);
        System.out.println(s1);
// DES数据解密
        String s2 = decryptBasedDes(s1);
        System.err.println(s2);
    }
}
